Home > Publications database > Bestimmung der Reaktionsgeschwindigkeit an Katalysatorpellets mit einem Wärmeflusskalorimeter |
Book/Report | FZJ-2018-02497 |
1985
Kernforschungsanlage Jülich, Verlag
Jülich
Please use a persistent id in citations: http://hdl.handle.net/2128/18207
Report No.: Juel-1989
Abstract: The aim of this work is the description of a time-saving and economical way to determine the rate of a heterogeneously catalyzed chemical reaction with a conventional heat flux DSC (Du Pont). Known calibration procedures for DSC-apparatus turn cut to be insufficient when .working with relatively large sample masses (catalyst pellets) and continuously changing gas concentrations. There is thus a requirement for detailed information about the heat transfer in the DSC cell in order to progress .from the single calibration experiment to a continuous caiculation of the calibration factor in definite parameter intervals. While the problems of conventional calibration are shown by the derivation of the calibration factor and by a survey of the literature, the main pari of this work describes a new way of Signal interpretation. Starting with theoretical studier, e. g. the steady state temperature profile of the constantan disc and the cylindrical sample with variable boundary conditions, a large number of different calibration Tuns lead to an easily applicable signal interpretation. The calibration factor was determined experimentally by the known melting heat of pure substances and by Evolved Gas Analysis with a gaschromatograph and mass spectrometer. Using this Cool, experiments were carried out studying CO methanation an Ni/Al$_{2}$O$_{3}$ catalysts. An equation to desbribe the reaction rate was derived and compared with Tates available in the literature. The wide range of DSC-applicabiiity is a consequence of the comparison of data determined by other types of reactors for the saure catalyst. The subsequent outlook shown more possibilities of DSC application in the f.ield of catalyst research.
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